Antenna tensioning device



@c 25, i935. H4 BRHE 2,234,925?

ANTENNA TENSIONLNG DEVICE Filed Feb. 24, 1936 Huang f -hx [A:

ATTORNEY Patented Oct. 25, 1938 UNrrso STATES ANTENNA TENSIONING DEVICE Herbert Brhe, Berlin, Germany, assigner to Siemens & Halske Aktiengesellschaft, Siemensstadt, near Berlin, Germany, a corporation of v f Germany Application February 24, 1936, Serial No. 65,533 In Germany March 22, 1935 2 Claims. (Cl. 267-71) In antenna arrangements on vehicles such as trains for train telephony, for example, it is of importance to provide antenna Wires which only sag a small amount. Consequently, they must always be maintained straight. The antenna conductors are, however, subjected to vibrations and high wind pressure so that in order to avoid breakage a yielding tensioning means should be provided. To this end spring arrangements or weights are inserted between the antenna support and the conductor. Such spring tensioners are subject to especially rapid destruction since they are continuously exposed to atmospheric conditions, especially frost and ice, and to chemically active constituents contained in the smoke of the locomotive especially effective in connection with humidity. These influences mainly cause deterioration of the material and finally lead to complete destruction.

My invention relates to anarrangement for tensioning antennas, and which is protected effectively against destructive inuences. According to the invention a helical spring producing the tensioning of the antenna is arranged within a weather proof, cup-shaped casing resting at one side against the cover of the casing and connected at the other side to a member attached to the antenna and inserted through the inner space of the spring and through the cover of the casing. Said member may constitute a cylindrical bolt, for example. The casing preferably consists of a material having high resistance against corrosion or it is coated with a paint, thereby resisting the destructive actions caused by the aforementioned influences for a long period of time. In order to prevent humidity or the like entering the interior of the tensioning device the casing is suitably filled-in with a grease resistible to acid and low temperatures, and serving at the same time as packing material for the passage of the bolt attached to the antenna. At this place of through passage the bolt is inserted with a certain play so as to obtain at this place always a sufcient lubrication.

The entrance of humidity and moisture between casing and cover is prevented by the provision of an interposed packing ring. At the cover the tensioning device rests against a support maintaining the antenna at a certain distance from the roof of the car and fastened to the casing by means of the screws used for fastening the cover in place.

For a better understanding of the -invention reference is made to the accompanying drawing in which the drawing shows a single embodiment thereof in partial section .along the axis of the device.

Numeral I represents the cup-shaped casing of the new tensioning device, closed at its open end by means of a cover 2 placed by means of an in- 5 terposed packing 3 of leather, rubber or the like upon the flange-shaped rim Il of the casing.

For fastening the cover, four screws 5 are employed equally distributed about its circumference and serving at the same time for fastening the l0 tensioning device to an angle-shaped support 'E which may be mounted on the roof 20 of the vehicle. In the casing I there is arranged a helical spring l shown in a greatly de-tensioned state resting at its right end against the inner side of l5 the housing cover 2 and attached at the left end to a plate-shaped flange 8 provided at the end of a bolt 9. This bolt is inserted through the cover and the guide bushing I0 fastened to the cover 2 and is attached to the antenna. It can readily be seen that in case of longitudinal variations of the antenna, such as shortening for instance, due to temperature influences or high wind pressure, the spring l will be compressed and the flangeshaped disk 8, together with bolt 9, is moved to 25 the right.

For fastening the antenna to the end of bolt 9 projecting from the guide bushing lil, a link I I is provided passed through a lateral bore I5 of the bolt. To provide a continuous tension in the antenna it is necessary that the device be mounted under a certain initial tension i. e. the spring l is in a tensioned state whereby the ange 8 is Withdrawn from the bottom I2 of the housing and the spring is compressed to about one-half of 35 the length thereof shown in the gure by means of the ange 8 and the bolt S. In this manner movement of the bolt in any direction of its .axis is assured so that it can adjust itself to any length of the antenna. 40

The guide bushing Ill is inserted through the bore I3 of the support 6. For the purpose of fastening the support 6, bores Ill are preferably provided in the part resting on the roof 20 of the car which serve to receive fastening screws or 45 bolts l I4 and the like.

As already pointed out, the interior of the housing is preferably filled in with a grease which is free of acid and p-roof against cold while continuously effecting a suicient sealing of the bolt 9 passing through the bushing Ill with sufficient play thereby preventing the entering of detrimental particles into the tensioning device and finally assuring a sufficient lubrication of the bearing.

Having described my invention, what Iclaim as novel and desire to secure by Letters Patent is:

1. Means for yieldingly supporting an antenna comprising in combination, a tubular casing closed at one end and open at the other, a member for rigidly supporting said casing, a cover plate having an aperture therein, securing means for attaching said cover plate to the openvend of said casing, a rod passing through said aperture, A a coil spring within the casing having one end connected to the inner end of said rod and the other end abutting the cover plate, a body of lubricant within said casing around said rod and spring, and means for connecting the outer end 15 of said rod to the antenna. Y

2. Means for tensioning and yieldably supporting one end of an antenna, said means comprising a rigidly supported tubular casing closed at one end, a rod member Within the casing and extending partly through the open end of the casing, a cover plate secured at the open end of the casing having an opening through which the rod member extends,`a helical spring contained Within the casing and encircling the rod member, one end of the spring being fastened to the inner end vof the rod and the other end of the spring abutting the cover plate, and means at the free end of the rod member to which the antenna is adapted to be attached.

HERBERT BRHE. 

